JP3064470B2 - Artificial prosthetic materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial prosthetic material, that is, a material for filling and prosthetic teeth or bone defects.

[0002]

2. Description of the Related Art It has long been practiced to replace and prosthetic teeth and bone defects with artificial materials. That is, artificial prosthetic materials that have been conventionally applied to living organisms include metal materials, organic materials, inorganic materials, and the like. However, strength, safety, affinity with living organisms, adhesion, and the like should be further improved. At present, the development of materials more similar to living organisms is ongoing.

[0003] In particular, one of the problems in repairing and repairing a tooth or bone defect using an artificial material is adhesion between a living body and the material.
It is that the artificial material and the living tissue form a stable state, but in order to improve such adhesion, hydroxyapatite,
Bioactive materials such as calcium triphosphate are known.
In these bioactive materials, it is said that apatite produced by osteoblasts in the living body and the material are integrated to cause bone adhesion.However, such a material is mainly semi-luxed and compared with living bone tissue. It has the disadvantage that the strength is relatively low, and that if the surface of the material is scratched, the strength is extremely reduced.

On the other hand, bioactive materials such as metal materials, carbon materials, alumina, and zirconia are superior in strength to living bone tissue, but are inferior to bioactive materials in adhesion to living bodies. . Therefore, in order to improve such adhesiveness, the surface of the material is provided with irregularities, or a porous structure layer is provided on the surface of the material so as to form a connective tissue similar to that of a living body, and a strong adhesiveness is generated by reaction with the living body. A method (Japanese Patent Publication No. 61-9859) and the like are known.

[0005]

However, although such a bioactive material or a bioinert material has its own characteristics in terms of adhesion to a living body, the period for completing such adhesion is about 2 to 3 in all cases. It takes a long period of a month, and it is necessary to keep the artificial prosthesis material in the implanted portion for such a period. If the standing and holding is insufficient, there is a problem that the period required for bonding is further extended or the bonding becomes impossible due to inflammation or the like.

[0006] In its this, the present inventors have result of intensive studies to solve such a problem, the substrate surface of the porous substrate surface
By attaching calcium phosphate compound together with biodegradable binder polymer to the inside of the pores without losing the porosity of the artificial prosthetic material, the adhesive strength of the artificial prosthetic prosthesis material is increased and the time required for adhesion is also increased The present inventors have found that they can be shortened in time, and arrived at the present invention. That is, an object of the present invention is to provide an artificial prosthetic prosthetic material with high properties that can be firmly adhered in a short time.

[0007]

SUMMARY OF THE INVENTION An object of the present invention, however, is to provide a porous base material having a porous surface with a reduced surface porosity.
Calcium phosphate compound up to the inside of the pores without causing
It is easily achieved by an artificial prosthetic material characterized in that it has been impregnated with a biodegradable binder polymer.

Hereinafter, the present invention will be described in more detail. The substrate used in the present invention may be any substrate conventionally used in this field, and is not particularly limited. Usually, various types of carbon fiber reinforced carbon materials and sintered carbon materials are used. Or a carbon material such as a glassy carbon material, or a metal such as platinum, titanium, tantalum, tungsten, and further, alumina, zirconia, calcium phosphate, titania,
Ceramics such as biological glass may be used. Among them,
It is preferable to use a carbon fiber reinforced carbon material, titanium, alumina, or the like in view of strength and biocompatibility as an artificial prosthetic material.

When the surface of the base material is porous, when implanted in a living body, a living tissue penetrates into the pores of the porous portion to form a strong connective tissue, which is preferable. If the surface of the substrate is porous, even if the biodegradable binder polymer and the calcium phosphate compound fall off from the vicinity of the substrate surface, they remain in the pores and do not lose the intended effect, making it easy to handle. There is also the advantage of becoming.

[0010] Above all, the connective tissue with the living body is calcified and bones
It is more preferable that the porous material can be changed into a tissue,
As such a porous material, specifically, alumina or
Pyrolytic carbon on a porous layer made of
And a carbonaceous porous layer formed by depositing carbon. A
As a porous layer made of lumina, for example,
No. 34731 is used.
It is. That is, Al_TwoO _ThreeOrganic binder (poly)
Spherical objects such as vinyl alcohol and polyethylene, chops
Mixed fiber, etc.)
The organic binder is burned and vaporized until the sintering temperature is reached.
It is a method of burning out and obtaining a porous layer composed of continuous pores.
You.

As the carbonaceous porous layer, Japanese Patent Publication No. Sho 6
Specific examples described in Japanese Patent Application Laid-Open No. 1-9859 are specifically used. For example, knitted fabrics, nonwoven fabrics, felts, papers using relatively long fibers of carbon fibers, chopped strands of relatively short fibers, etc. On the surface of the core material. At this time, when using a woven fabric, a nonwoven fabric, felt, paper, or the like, cut them into appropriate sizes and attach them using an organic adhesive as necessary, and further, if necessary, wind and fix them with long fibers. . In the case of using chopped strands, a method is adopted in which an organic adhesive is applied to a necessary portion of the substrate surface, and the chopped strands are adhered and fixed so as to cover the organic adhesive. Next, pyrolytic carbon is deposited on the obtained material (hereinafter referred to as a deposition carbon material) to be integrated. In this pyrolytic carbon treatment, the temperature of the base material is set to 600 ° C. or more and 2300 ° C. or less, desirably 700 to 1100 ° C., so that a state having a negative temperature gradient from the base material toward the surface is formed, Precipitation is suitable for forming an excellent carbonaceous porous layer.

[0012] Such a carbonaceous porous layer typically has a structure in which, for example, a large number of fibers overlap in a random direction and are firmly bound to each other. In the vicinity of the surface, pores having a pore size of 100 μm or more, preferably 200 μm or more are included, and the pore size decreases toward the inside of the substrate. That is, a porous layer having a porosity distribution in which the porosity gradually decreases toward the inside is preferable. Further, in the case of an artificial root material, it is preferable to provide a non-circular cross-sectional portion having a threaded structure or a non-threaded structure in a part of the base material because falling can be physically prevented.

[0013] The present invention relates to a method for preparing calcium phosphate on a substrate surface.
Impregnate compound with biodegradable binder polymer
It is characterized by having made it. As a calcium phosphate compound
For example, anhydrous dicalcium phosphate (CaHPO_Four), Piro
Phosphate lime (Ca_TwoP_TwoO₇), Brushite (CaH
PO_Four2H_TwoO), tricalcium phosphate (Ca_Three(PO
_Four)_Two), Hydroxyapatite (Ca _Ten(PO_Four)
₆(OH)_Two) And the like, of which
Due to strength, tricalcium phosphate, hydroxyapatite
Or mixtures thereof, but are not limited thereto.
Not something.

The osteoinductive action of the calcium phosphate compound is an action that promotes the growth of fibrous biological tissue on the surface of the base material and changes into bone tissue. In particular, this effect
When the surface of the base material is porous, the fibers forming the porous material and the living tissue form a double stitch structure entangled with each other, which is effective for realizing strong adhesion. The calcium phosphate compound may be used in an amount necessary and sufficient to express the above-mentioned osteoinductive action. Specifically,
It is appropriate to use an amount capable of forming a layer of 0.1 μm or more on the substrate surface.

When the surface of the substrate is porous, it is appropriate to use the layer in an amount of about 0.1 μm or more on the surface of the pores near the surface of the substrate. It is preferable to form a calcium phosphate compound having a thickness of 0.1 μm or more on the surface of all the internal pores. However, if the amount of the calcium phosphate compound to be impregnated is too large to close the pores, it may adversely affect invasion of living tissue.

As the biodegradable binder polymer, any known polymer can be used, and examples thereof include poly (3-hydroxybutyrate-4 hydroxybutyrate), poly-3-hydroxybutyrate, and poly (3-hydroxybutyrate). Examples thereof include -3 hydroxyvalerate, polylactic acid, polyglycolic acid, polycaprolactone, polyethylenerenadipate, polybutylenadipate, and polyhydroxyalkanoate.

Among them, polyhydroxybutyrate (PH)
B), polylactic acid and the like are particularly preferred in that they are easily dissolved in an organic solvent such as chloroform and are insoluble in water. These can be easily attached to the substrate surface by dissolving in an organic solvent and applying. Also, if the binder polymer is water-soluble, it may dissolve in biological fluids, and the calcium phosphate compound may be released from the surface of the base material, and may not exhibit the intended effects such as osteoinductive action. There is no fear at all.

The amount of the biodegradable binder polymer used is
An amount sufficient to bind the calcium phosphate compound particles to each other and to bind the calcium phosphate compound particles to the base material and to such an extent that the surface of the calcium phosphate compound is not completely covered and the osteoinductive action is not impaired is preferable. Specifically, 2 to 50% by weight, preferably 5 to 30% by weight of the amount of the calcium phosphate compound is appropriate.

In the present invention, the use of the biodegradable binder polymer shortens the time required for adhesion as compared with the case where the calcium phosphate compound is used alone. It is considered that this is because the living tissue is quickly replaced by being absorbed by biodegradation. The method of adhering calcium phosphate to the substrate surface together with the biodegradable binder polymer is not particularly limited, but a slurry in which a calcium phosphate compound is dispersed in a solution obtained by dissolving the biodegradable binder polymer in a solvent is immersed in the substrate surface. A method of applying by a method such as application or spray application is easy and efficient without being particularly affected by the surface condition of the substrate. Further, when the surface of the base material is porous, according to the method of dip coating the slurry, once the slurry enters the inside of the pores, only the solvent evaporates. It is possible to apply to the inside of the pores without, preferably, further, a vacuum impregnation method in which the substrate is placed in a container, air or the like inside the pores is sucked out by reducing the pressure, and then normal pressure or high pressure is applied. It is suitable.

Further, the artificial prosthetic prosthesis of the present invention is characterized in that a calcium phosphate compound and a biodegradable binder polymer are attached to the surface of a base material. It is not limited only to the binder polymer, and other components may be used together if necessary. For example, in the case of manufacturing a slurry, sucrose fatty acid ester, glyceryl monotearate (MSG), sesquisulfate, etc. may be used as necessary to prevent uneven attachment of the calcium phosphate compound and blockage of surface pores due to agglomerates. A dispersant such as sorbitan oleate may be used.

Furthermore, when preparing a slurry, the order of mixing the binder and the dispersant is also important because it affects the dispersibility of the calcium phosphate compound. A dispersion medium in which a calcium phosphate compound and a dispersant are dissolved is partially dispersed and pulverized in a dispersion container for a predetermined time, and then a dispersion medium in which a binder is dissolved is added, followed by further dispersion and pulverization. A ball mill, a vibrating ball mill, a paint shaker and the like which are usually used are used for the dispersion and pulverization.

The slurry thus dispersed is impregnated into the carbon porous layer. Specifically, at this time, the pressure is reduced to the root material, the slurry is introduced, and the pressure is returned to the normal pressure after a predetermined time, whereby the slurry is impregnated into the inside of the porous layer. In addition,
When the dispersion medium is water, it is preferable to perform a hydrophilic treatment on the carbon surface prior to impregnation because the wettability between the slurry and the porous carbon is poor. For the hydrophilization treatment, techniques such as wet oxidation with acid and dry oxidation with oxygen are used, but treatment with oxygen and air plasma is desirable because the core material is mild.

[0023]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples unless it exceeds the gist. Example 1 Carbon fiber was used for a titanium core material with a pillar head having a diameter of 3.2 mm and a length of 1.5 mm and a pillar foot having a diameter of 1.9 mm and a length of 9.5 mm. Wind the felt to a thickness of 5 mm. After heating this sample to 700 ° C. by high-frequency induction heating in the reactor, dichloroethylene vapor is introduced into the reactor using argon gas as a carrier gas to generate pyrolytic carbon. After the reaction for one hour, a material having a porous structure layer having open pores on the surface is obtained in which the titanium core material and the carbon fiber are bonded and integrated with pyrolytic carbon. The surface condition of this material was adjusted with a grinder for work, and the diameter was 3.
A base material having a titanium head having a length of 2 mm and a total length of 11.6 mm and having a carbonaceous porous structure layer having open pores on its surface is prepared.

2 g of hydroxyapatite (HAP) particles having an average particle size of 2 μm and glycerin monostearate (M
SG) 0.1 g, chloroform 40 g, PHB (polyhydroxybutyrate) 0.4 g, chloroform 57.5
g in a container having an inner volume of 140 ml together with 70 g of dispersion spheres, and a paint shaker treatment was carried out for 6 hours to disperse HAP in chloroform, and then HAP2 / MSG0.1 / PH.
A slurry of B0.4 / chloroform 97.5 (% by weight) was obtained.

This slurry was vacuum impregnated into the above-mentioned base material having a carbonaceous porous layer, dried, and HAP was spotted to produce an artificial prosthetic material. When the surface and the inside of the porous layer of the prosthetic material were observed with a scanning electron microscope (SEM), the thickness was about 2 μm near the surface and 0.1 mm inside.
A μm HAP layer was formed, and no pore blockage was observed. Further, the prosthetic prosthetic material was embedded in the femur of a Japanese macaque, sacrificed after a certain period of time, the femur was taken out, and the shear adhesive strength with the prosthetic prosthetic material was measured using a mechanical property analyzer manufactured by Minebea, It measured using TCM5000A ". Table 1 shows the results.

[0026] Comparative Example Example 1 and exactly the same way substrates were prepared, Table 1 shows the result of in the same manner as in Example 1 except that the implanted directly into the femur of a Japanese monkey is not impregnated with HAP.

[Table 1]

[0027]

The artificial prosthetic material of the present invention can be used
It can be firmly bonded in a shorter time than conventional products, can be easily manufactured, and offers great industrial benefits.

────────────────────────────────────────────────── ─── Continued on the front page (73) Patent holder 000005968 Mitsubishi Chemical Corporation 2-5-2, Marunouchi, Chiyoda-ku, Tokyo (72) Inventor Suguro Otani 2010-2, Hishimachi Kurokawa 2010-2 (72 Inventor ▲ Yanagi ▼ Sadakatsu Sawa 2-34-3, Mita, Minato-ku, Tokyo (72) Inventor Kunio Niijima 563, Kamikomachi, Omiya City, Saitama Prefecture No. 1000, Mitsubishi Kasei Research Institute (72) Inventor Hiroshi Machino 1000, Kamoshita-cho, Midori-ku, Yokohama, Kanagawa Prefecture, Japan Inside (72) Inventor Tohru Fuse 1000, Kamoshita-cho, Midori-ku, Yokohama, Kanagawa Address Mitsubishi Chemical Corporation Research Laboratory (56) References JP-A-61-33660 (JP, A) JP-A-2-241461 (JP, A) JP-B-61-9598 (JP, B ) Real public Akira 56-34731 (JP, Y2) (58 ) investigated the field (Int.Cl. ^7, DB name) A61L 27/00

Claims (1)

(57) [Claims] To 1. A porous substrate surface of a porous substrate surface
An artificial prosthetic material comprising a calcium phosphate compound and a biodegradable binder polymer attached to the inside of pores without losing water.